Thermoplastic polyurethanes are usually produced by reacting a polyol compound with a diisocyanate and a chain extender and have linear polymeric molecular structures having hard segment portions and soft segment portions. Thermoplastic polyurethanes formed in accordance with this general recipe have various properties including a wide variety of moisture vapor transmission (MVT) rates.
U.S. Pat. No. 6,613,867 relates to thermoplastic polyurethanes (TPUs) or thermoplastic polyurethane/ureas (TPUUs) that comprise structural units of: a) a diisocyanate; b) ethylene glycol, diethylene glycol, or 1,3-propanediol; c) a diol, a diamine, or an amino alcohol different from the one selected in (b) and having a molecular weight of less than 400 Daltons; and (d) ethylene oxide polyol or ethylene oxide-capped propylene oxide polyol.
U.S. Pat. No. 6,984,709 relates to breathable thermoplastic polyurethanes that are prepared from the reaction of a polyol component, a polyisocyanate component, and a chain extender in the presence of a metal-free catalyst. The metal-free catalyst is disclosed as a polyalcohol amine, a tertiary amine catalyst, or a combination thereof.
It is a long accepted believe in the art that thermoplastic polyurethane polymers made from poly(ethylene oxide) polyols give the highest moisture vapor transmission rates. It would be beneficial to improve (increase) the moisture vapor transmission of a poly(ethylene oxide) based thermoplastic polyurethane polymer.